JP2006512872A - Method and system for preventing call disconnection between the 1xEV-DO system and a hybrid terminal by limiting a search time for the 1X system in a traffic state with the 1xEV-DO system - Google Patents

Abstract

The present invention supports both the 1xEV-DO system and the 1X system, and periodically switches to the 1X system in the traffic state with the 1xEV-DO system to update the overhead message and confirm the search time. A base station transmitter including a hybrid terminal that converts to a 1xEV-DO system based on a 1xEV-DO transmitter that exchanges packet data with the hybrid terminal and a 1X transmitter that exchanges voice or data; A base station controller including a 1xEV-DO controller for controlling packet data transmission service of the 1xEV-DO transmitter and a 1X controller for controlling transmission service of the 1X transmitter; and packet data between the 1xEV-DO system; Packet data servers connected to the 1xEV-DO system to exchange Consisting of the Bing node.

Description

  The present invention relates to a method and system for preventing call disconnection that occurs between the 1xEV-DO system and a hybrid terminal by limiting a search time for the 1X system in a traffic state with the 1xEV-DO system. If the hybrid terminal maintains the 1X mode for a predetermined time or longer, the call disconnection of the hybrid terminal executed by the 1xEV-DO system is performed, and the 1X system in the hybrid terminal in traffic state with the 1xEV-DO system. It is related with the method and system which prevent by limiting the search time with respect to within predetermined time.

  The mobile communication system has been remarkably developed through the first generation analog type AMPS (Advanced Mobile Phone Systems) and the second generation mobile phone / PCS (Personal Communication Service) system. Recently, IMT-2000 (International Mobile Telecommunication-2000) has been developed and widely used as a third generation high-speed data communication system.

  3GPP2 (3rd Generation Partnership Project 2), which is a joint international standardization organization, provides the CDMA IMT-2000 system standard as an IMT-2000 standard for providing multimedia mobile communication services. According to this standard, a high-speed packet transmission system called 1xEV (Evolution) adopting HDR (High Data Rate) proposed by Qualcom is an international standard for high-speed packet transmission systems. The CDMA2000 1xEV-DO (Data Optimized or Data Only) system has evolved from the CDMA2000 1X system and is designed for data-only transmission.

  For convenience of explanation, in the following description, the CDMA2000 1X system is abbreviated as “1X system”, and the CDMA2000 1xEV-DO system is abbreviated as “1xEV-DO system”.

  The 1X system provides a high-speed data service with a maximum transmission rate of 307.2 kbps by using both a circuit network and a packet network. In contrast, the 1xEV-DO system is dedicated to packet data and provides a high-speed packet data service with a maximum transmission rate of 2.4 Mbps.

  Currently, the 1xEV-DO system is used together with the conventional 1X system. That is, both the 1xEV-DO system and the conventional 1X system are installed in one radio base station or one base station controller, although they operate separately from each other. In other words, the transmitter of the radio base station includes a channel card for 1xEV-DO system and a channel card for 1X system. Further, the base station controller includes a data processing board for processing packet data transmitted through the 1xEV-DO system and a data processing board for processing data transmitted through the 1X system.

  High-speed data is transmitted from a mobile communication system such as a radio base station or a base station controller to a mobile communication terminal through a 1xEV-DO system. The voice signal or low-speed data is transmitted to the mobile communication terminal through the 1X system.

  The hybrid terminal is a mobile communication terminal that can receive communication services transmitted from both the 1xEV-DO system and the 1X system, and periodically monitors the 1X system and the 1xEV-DO system alternately at predetermined time intervals. . That is, the hybrid terminal periodically searches the 1X system and the 1xEV-DO system alternately in the standby state, and periodically searches the 1X system in the traffic state with the 1xEV-DO system.

  Specifically, a hybrid terminal that is in traffic with the 1xEV-DO system can respond to a low-speed data communication signal such as a voice incoming call acceptance signal or a short message that may be transmitted from the 1X system. And periodically update system resources such as system messages and access messages.

  However, even when the hybrid terminal is in traffic with the 1xEV-DO system, it periodically connects to the 1X system and maintains the connection with the 1X system until the system resources are completely updated.

  On the other hand, the 1xEV-DO system executes a call drop when a signal from a hybrid terminal in a traffic state is not received within a predetermined time interval (for example, 5.12 seconds). In other words, if the signal from the hybrid terminal does not detect the signal from the hybrid terminal within a predetermined time interval regardless of the cause, the 1xEV-DO system is connected to the hybrid terminal in order to use system resources efficiently. Perform release.

  However, the call connection cancellation lowers the reliability of the communication service and causes trouble for users who do not wish to cancel the call connection with the 1xEV-DO system.

  The present invention has been made in view of such problems, and its purpose is to cancel the call connection of a hybrid terminal executed by the 1xEV-DO system when the hybrid terminal maintains the 1X mode for a predetermined time or longer. Is provided by limiting the search time for the 1X system in a hybrid terminal in traffic with the 1xEV-DO system to be within a predetermined time.

  In order to solve the above problems, according to an aspect of the present invention, a predetermined search time for a 1X system is limited in a traffic state with a CDMA 2000 1xEV-DO (1xEV-DO) system, and the 1xEV-DO system A system for preventing call connection cancellation with a hybrid terminal, wherein the 1X mode receives a voice signal transmission service or a low-speed data transmission service from the 1X system in conjunction with the 1X system, and the 1xEV-DO system. The 1xEV-DO mode that receives a high-speed data transmission service from the 1xEV-DO system in conjunction with the 1xEV-DO system functions in the 1X mode in order to update overhead messages in the 1xEV-DO system and the traffic state. Periodically converted, at the time of the predetermined search Voice or data between the hybrid terminal that is returned to the 1xEV-DO mode after a lapse of time; a 1xEV-DO transmitter that transmits / receives packet data to / from the hybrid terminal, and the hybrid terminal A base station transmitter including a 1X transmitter for transmitting and receiving data; a 1xEV-DO controller for controlling packet data transmission service of the 1xEV-DO transmitter; and a 1X controller for controlling transmission service of the 1X transmitter; A base station controller including: a packet data serving node (PDSN) connected to the 1xEV-DO controller for transmitting and receiving the packet data to and from the 1xEV-DO system; Call connection with a limited search time for the 1X system in the traffic state with the 1xEV-DO system System for preventing removal is provided.

  In order to solve the above problem, according to another aspect of the present invention, a call connection is canceled by limiting a predetermined search time for a 1X system in a traffic state with a CDMA 2000 1xEV-DO (1xEV-DO) system. (A) the hybrid terminal sequentially initializes the 1X mode and the 1xEV-DO mode and maintains a standby state; and (b) the hybrid terminal is in the standby state. Periodically and alternately performing monitoring on the 1X system and the 1xEV-DO system; (c) the hybrid terminal transitions to the traffic state of the 1xEV-DO mode, and the 1xEV-DO system 1xEV-DO system by forming a connection and session with Enabling transmission / reception of packet data to and from (d) a step of switching the hybrid terminal to the 1X mode after elapse of a predetermined monitoring time; and (e) the hybrid terminal When switching to 1X mode, the step of checking the switching time and detecting the signal of the 1X system; and (f) when the switching time reaches a predetermined return start time, the hybrid terminal makes the 1xEV-DO. Returning to the mode, and a call generated between the 1xEV-DO system and the hybrid terminal by limiting a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system. A method for preventing disconnection is provided.

  In order to solve the above problem, according to still another aspect of the present invention, a predetermined search time for a 1X system is limited in a traffic state with a CDMA 2000 1xEV-DO (1xEV-DO) system to limit the 1xEV. A hybrid terminal for preventing call connection cancellation between the DO system and the hybrid terminal, the timer measuring a switching time when the 1xEV-DO mode is switched to the 1X mode; A searcher module that tracks and changes frequencies to perform the conversion between a mode and the 1xEV-DO mode and receives overhead messages; a finger module that demodulates the overhead messages received from the searcher module; The 1X system and the 1xEV-DO cis And an MSM chip that generates a return control signal and transmits it to the searcher module when receiving a return start signal from the timer when searching for the 1X system. A hybrid terminal is provided that prevents call disconnection by limiting a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system.

  As described above, in the related art, when a hybrid terminal that is in traffic with the 1xEV-DO system searches the 1X system, the call connection is released due to various causes. However, according to the present invention, by limiting the search time for the 1X system, the hybrid terminal can return to the 1xEV-DO mode before the call disconnection with the 1xEV-DO system occurs. Call disconnection can be resolved.

  Further, according to the present invention, the hybrid terminal itself checks the search time for the 1X system without using the resources of the 1X system and the 1xEV-DO system, and returns to the 1xEV-DO mode. It is possible to prevent system overload and waste of communication resources.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, the invention specifying items having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic block diagram illustrating a system 100 that limits a search time for a 1X system in a hybrid terminal 110 to prevent call disconnection of the hybrid terminal 110 according to an embodiment of the present invention.

  As shown in FIG. 1, a system 100 according to the present invention comprises both a 1xEV-DO system and a 1X system. That is, the system 100 includes a 1X transmitter 122, a 1X controller 132, and a mobile switching center (MSC) 140, and includes a 1X system that performs voice and data communication with the hybrid terminal 110. Further, the system 100 includes a 1xEV-DO (connection network) transmitter (ANTS: Access Network Subsystem) 124, a 1xEV-DO (connection network) controller (ANC: Access Network Controller) 134, and a packet data serving node (PDSN). A 1xEV-DO system that includes only a packet data serving node (IP) 150 and an IP (Internet Protocol) network 160 and performs data communication only with the hybrid terminal 110 is provided.

  The hybrid terminal 110 is divided into two operation units that operate separately in a part that receives a voice service and a low-speed data service from the 1X system and a part that receives a high-speed data service from the 1xEV-DO system. In the standby state, the hybrid terminal 110 is switched to the 1X mode so that it can communicate with the 1X system. In this state, the hybrid terminal 110 is periodically switched to the 1xEV-DO mode at a predetermined time interval and returns to the 1X mode again in order to confirm whether there is data reception from the 1xEV-DO system. According to an embodiment of the present invention, switching the hybrid terminal 110 in traffic with the 1xEV-DO system to the 1X mode is referred to as “switching” and switching to the 1xEV-DO mode is referred to as “switching”. Called 'Return'.

  The conversion and recovery operations performed between the 1X system and the 1xEV-DO system are mobile station modems (MSMs) that are a type of baseband modem chip mounted on the hybrid terminal 110. It is controlled using software installed on the chip. Furthermore, the conversion and return operations are realized by tracking the frequency of each network using a searcher connected to the MSM chip. That is, when the hybrid terminal 110 is switched from the 1xEV-DO mode to the 1X mode, the searcher module tracks the frequency of the 1X system under the control of the MSM chip. Furthermore, when the hybrid terminal 110 returns from the 1X mode to the 1xEV-DO mode, the searcher module tracks the frequency of the 1xEV-DO system.

  When the hybrid terminal 110 receives data from the 1xEV-DO system in the 1xEV-DO mode, a large amount of data is received because the hybrid terminal 110 receives high-speed data. Therefore, in the case of a forward link that transmits data from the access network (AN) to the hybrid terminal 110, a channel divided by a CDMA (Code Division Multiple Access) method is a TDM (Time Division Multiplexing) method. The data is transmitted through time slots divided by. In contrast, in the case of a reverse link that transmits data from the hybrid terminal 110 to the 1xEV-DO transmitter 124 and the 1xEV-DO controller 134, it is conventional for multiple subscribers. Data is transmitted through the CDMA system.

  In addition, the hybrid terminal 110 that receives data in the traffic state of the 1xEV-DO mode periodically switches to the 1X mode at a predetermined time interval in order to check whether there is an incoming signal such as a voice incoming call through the 1X system. And return to 1xEV-DO mode again.

  The 1X transmitter 122 and the 1xEV-DO transmitter 124 are provided with a base station transmitter (BTS) in order to provide the mobile terminal 110 with a mobile communication service including voice and data through a contactless interface (air interface). (Subsystem) 120 is configured. That is, the base station transmitter 120 transmits voice or data to the hybrid terminal 110 through the 1X transmitter 122 and transmits only packet data through the 1xEV-DO transmitter 124.

  The 1X controller 132 and the 1xEV-DO controller 134 constitute a base station controller (BSC) 130 that controls the operation of the base station transmitter 120. That is, the 1X controller 132 that controls the transmission of voice or data transmits the voice and / or data transmitted from the 1X transmitter 122 to the mobile communication switching center 140, and the 1xEV-DO controller 134 transmits the 1xEV-DO. Data transmitted from the transmitter 124 is transmitted to the PDSN 150.

  In order to provide a communication connection path of a 1X system for a communication call transmitted from the hybrid terminal 110, the mobile switching center 140 connects a plurality of 1X controllers 132 to other mobile switching centers or A physical connection is made to a public switched telephone network (PSTN) 146.

  In addition, the mobile communication switching center 140 has a location information register (HLR) 142 that is a database for storing information of the hybrid terminal 110 registered in the switching center 140 and an area of the switching center 140. The subscriber's call signal is processed by obtaining the profile information of the hybrid terminal 110 from the visitor information register (VLR) 144 which is a database for storing information of the hybrid terminal 110 located. To do. Here, the profile information includes information related to MIN (Mobile Identification Number), ESN (Electrical Serial Number), and additional services.

  The 1xEV-DO system, which is a high-speed packet data system, is connected to the PDSN 150 based on TCP / IP, and transmits and receives various data to and from the IP network 160 in the form of IP packets. The 1xEV-DO system receives packet data from the IP network 160 and transmits the packet data to the hybrid terminal 110 through time slots divided by the TDM method. The 1xEV-DO system receives CDMA data modulated by the CDMA method from the hybrid terminal 110, generates packet data using the CDMA data, and transmits the packet data to the PDSN 150.

  In the case of the forward link, the 1xEV-DO system transmits data at the maximum power without using the power control of the radio base station, and provides only a hard handoff function. On the other hand, in the case of the reverse link, power control is performed in each terminal, and a soft handoff function is provided in the same manner as the hard handoff function.

  2a and 2b are block diagrams illustrating a channel structure of a forward link for transmitting data to the hybrid terminal 110 through the 1xEV-DO transmitter 124.

  As shown in FIG. 2a, the forward link includes a pilot channel, a MAC (Medium Access Control) channel, a control channel, and a traffic channel. The pilot channel transmits a pilot signal for tracking the hybrid terminal 110 in the 1xEV-DO system. The hybrid terminal 110 receives one or more pilot signals through the pilot channel and connects to the radio base station that has transmitted the strongest signal. Also, the pilot channel is used as a reference for performing coherent detection of a radio base station having a 1xEV-DO system using the hybrid terminal 110.

  The MAC channel is mainly used to control the reverse link, and includes an RA (Reverse Activity) channel and an RPC (Reverse Power Control) channel. Here, the RA channel is used to determine the transmission rate of the reverse link. Further, when the reverse link channel is in a saturated state, the RA channel is used to request the hybrid terminal 110 to reduce the transmission rate. In addition, when the hybrid terminal 110 transmits a signal or data through the reverse link, the RPC channel is used to control transmission power.

  The control channel is used to transmit a broadcast message or a direct message for directly controlling a specific hybrid terminal from the 1xEV-DO system to the hybrid terminal 110. The traffic channel is used when the 1xEV-DO system transmits only packet data to the hybrid terminal 110.

  In the following, as shown in FIG. 2b, the time slot structure and data structure in the forward link will be described in detail. First, the forward link includes 16 time slots per frame with a time interval of approximately 26.67 ms. Further, each time slot has a total of 2048 chips, including a first half slot 1024 chips and a second half slot 1024 chips. In addition, a time interval of 1.67 ms is assigned per time slot.

  Specifically, the first half and the second half slot include a data slot 400 chip, a MAC slot 64 chip, a pilot slot 96 chip, a MAC slot 64 chip, and a data slot 400 chip, respectively.

  FIG. 3 is a block diagram illustrating a reverse link channel structure for transmitting data from the hybrid terminal 110 to the 1 × EV-DO transmitter 124.

  The reverse link shown in FIG. 3 uses the CDMA method as in the 1X system, and mainly includes an access channel and a traffic channel. The access channel has a pilot channel and a data channel, and the traffic channel has a pilot channel, a MAC channel, an answer (Ack) channel, and a data channel. Here, the MAC channel is further divided into an RRI (Reverse Rate Indicator) channel and a DRC (Data Rate Control) channel.

  The access channel is used to transmit an origination message (origination connection_request message) and a registration message (registration route_update message). The access channel has a low transmission rate of 9.6 kbps because of the stability of the radio channel.

  The pilot channel shown in FIG. 3 is used as a reference for performing synchronous detection of a radio base station having a 1xEV-DO system using the hybrid terminal 110, similarly to the pilot channel of the forward link shown in FIG. 2a. . The data channel is used to transmit data required when the hybrid terminal 110 is connected to the 1xEV-DO system.

  The traffic channel is used when the hybrid terminal 110 transmits packet data to the 1xEV-DO system. The traffic channel provides various data transmission speeds depending on the wireless communication environment.

  The pilot channel performs the same function as that of the pilot channel as described in connection with the access channel. The MAC channel is used to control the data transmission rate of the traffic channel, and exists for a period in which the hybrid terminal 110 is connected to the 1xEV-DO system. When the hybrid terminal 110 transmits data through the traffic channel, the RRI channel of the MAC channel indicates information on the data transmission rate of the traffic channel. The RRI value is displayed on the hybrid terminal 110.

  Also, the DRC channel determines the transmission rate of data that can be demodulated according to the channel environment of the forward link, and notifies the base station. That is, the 1xEV-DO transmitter 124 transmits packet data to the hybrid terminal 110 using a forward link time slot. At this time, the DRC cover value transmitted by the hybrid terminal 110 serves as a reference for determining the transmission rate of the packet data. The hybrid terminal 110 measures the carrier-to-interference (C / I) value transmitted from the 1xEV-DO transmitter 124 to determine the DRC cover value, and realizes the maximum transmission rate. Determine the DRC cover value to obtain.

  The Ack channel is used to transmit a response signal for data received through the forward link in units of time slots by the hybrid terminal 110, and is suitable for data having a short data length. It corresponds to / 2.

  Similar to the data channel of the access channel, the data channel is used when the hybrid terminal 110 transmits only packet data.

  On the other hand, a packet which is a basic transmission unit of a traffic channel has a length of 26.66 ms, and the transmission bit rate changes according to the packet size. The pilot channel, traffic channel, DRC channel, and Ack channel are distinguished from each other using a Walsh code that is an orthogonal code.

  FIG. 4 is a diagram illustrating a method of limiting the search time for the 1X system in the hybrid terminal 110 to prevent the call disconnection of the hybrid terminal 110 in a traffic state with the 1xEV-DO system according to an embodiment of the present invention. It is a figure which shows a procedure.

  The search time according to an embodiment of the present invention refers to a call request such as voice communication, reception of a short message service (SMS) after the hybrid terminal 110 in traffic with the 1xEV-DO system returns to the 1X mode, And a period of time required for overhead messages to be updated in order to perform location registration.

  As shown in FIG. 4, the hybrid terminal 110 using packet data in the traffic state with the 1xEV-DO system checks a predetermined time interval (for example, 5.12 seconds) in order to confirm whether there is a call request by the 1X system. Will switch to 1X mode and search for 1X system. The hybrid terminal 110 updates the overhead message in order to execute a call request process and a location registration process transmitted from the 1X system while the connection with the 1X system is maintained.

  Here, the call request means that a voice call request or SMS is transmitted to the hybrid terminal 110. The overhead messages include a system parameter message, an access parameter message, an extended system parameter message, a neighbor list parameter message, and a channel list parameter message.

  The system parameter message includes an NID (Network ID), an SCI (Slot Cycle Index), a packet zone ID (packet zone ID), and the like required for incoming calls. The access parameter message includes information required for the hybrid terminal 110 to connect from the 1xEV-DO system to the 1X system. The extended system parameter message includes a system parameter added by an improvement from IS (Interim Standard) -95B system to 1X system. In addition, the neighbor list parameter message includes information on cell IDs of neighboring cells adjacent to the cell where the hybrid terminal 110 is located. The channel list parameter message includes information about frequency channels on which the hybrid terminal 110 can form a call and transmit or receive data or voice.

  In a mobile telecommunications environment using both the 1xEV-DO system and the 1X system, the hybrid terminal 110 maintains the 1X mode until all the overhead messages described above are updated while monitoring the 1X system. However, if the signal from the hybrid terminal 110 is not detected within a predetermined time interval (for example, 5.12 seconds according to the standard), the 1xEV-DO system releases the call connection to the hybrid terminal 110. Execute.

  Therefore, according to the present invention, the hybrid terminal 110 can be used after the switching to the 1X mode, so that the call connection is not canceled between the hybrid terminal 110 switched to the 1X mode and the 1xEV-DO system. Return to 1xEV-DO mode within 12 seconds. Such a function is realized in the hybrid terminal 110.

  Specifically, the hybrid terminal 110 forcibly returns from the 1X mode to the 1xEV-DO mode through the built-in MSM chip, searcher module, finger module, and timer. The MSM chip has a function of processing and controlling various operations occurring in the hybrid terminal 110, and input / output through the hybrid terminal 110, 1xEV-DO system, 1X system, and a user who inputs voice and key values. And / or control various data sent and received. The MSM chip includes a central processing unit (CPU) and a voice encoding vocoder.

  Accordingly, when the hybrid terminal 110 is in a traffic state with the 1xEV-DO system, the MSM chip performs a monitoring operation on the 1X system at intervals of one cycle using the built-in software. Such a monitoring operation is realized through a searcher module. That is, the searcher module performs the monitoring operation by tracking the frequency of the 1X system at predetermined time intervals under the control of the MSM chip.

  Meanwhile, a modulation signal or data received through the searcher module during monitoring of the 1X system by the searcher module is transmitted to the MSM chip and then transmitted to the finger module by the MSM chip. The finger module that receives the modulation signal or data from the MSM chip demodulates the modulation signal or data using a CDMA demodulation technique. Also, the modulated signal or data received through the searcher module during monitoring of the 1xEV-DO system by the searcher module is demodulated using a TDMA demodulation technique.

  Meanwhile, according to the technical phenomenon of the present invention, the MSM chip switches from the 1xEV-DO mode to the 1X mode for searching for the 1X system, and activates the built-in timer of the hybrid terminal 110. The timer transmits a predetermined return start signal to the MSM chip when a predetermined return time elapses while receiving an operation control signal from the MSM chip for measuring the conversion time.

  That is, according to the technical phenomenon of the present invention, the MSM chip or timer stores predetermined return start time information for the hybrid terminal 110 that searches for the 1X system by switching to the 1X mode to return to the 1xEV-DO mode. is doing. Accordingly, the MSM chip that has received a predetermined return start signal from the timer ends the search for the 1X system, generates a return control signal, and transmits it to the searcher, whereby the hybrid terminal returns to the 1xEV-DO mode. At this time, the MSM chip uses the stored return start time to check whether the conversion time measured by the timer reaches the return start time, generates a return control signal, and transmits it to the searcher. .

  Meanwhile, according to an embodiment of the present invention, the hybrid terminal 110 converted to the 1X mode searches for an overhead message over a predetermined search time corresponding to “SCI = 1” to “SCI = 3”. Here, since “SCI = 1” is 1.12 seconds in the standard, the return start time for returning the hybrid terminal 110 from the 1X mode to the 1xEV-DO mode is 3.36 seconds (1. 12 seconds × 3). In other words, after the hybrid terminal 110 is switched to the 1X mode, the MSM chip uses the timer to check the time of 3.36 seconds, stops the search operation for the 1X system, and the hybrid terminal 110 detects the 1xEV. -Return to DO mode.

  On the other hand, considering that the call disconnection of the 1xEV-DO system occurs 5.12 seconds after the switch of the hybrid terminal 110 to the 1X mode, the search time for the hybrid terminal 110 according to the present invention to search the 1X system is increased. It is desirable to set it to 3.36 seconds. At this time, since the hybrid terminal 110 has a 1.76 second surplus time until the call connection with the 1xEV-DO system is released, it can stably return to the 1xEV-DO system. Of course, according to an embodiment of the present invention, the recovery start time is set to 3.36 seconds corresponding to 'SCI = 3' in consideration of the stable recovery of the hybrid terminal 110. May be set to 4.48 seconds corresponding to 4 ″. In this case, since the hybrid terminal 110 has a margin time of 0.64 seconds before returning to the 1xEV-DO mode, it can stably return to the 1xEV-DO system.

  Meanwhile, signals and data received and demodulated when the hybrid terminal 110 is switched to the 1X system and maintained in connection are stored in the internal memory of the hybrid terminal 110. Accordingly, the hybrid terminal 110 returns to the 1xEV-DO mode, operates in a traffic state with the 1xEV-DO system, and returns to the 1X mode again after a predetermined time (for example, 5.12 seconds) has elapsed. At this time, if the hybrid terminal 110 receives and demodulates only the overhead message excluding the overhead message obtained by the search operation for the previous 1X system, call processing in the 1X system becomes possible.

  FIG. 5 illustrates a call connection between a hybrid terminal 110 and a 1xEV-DO system in a traffic state with the 1xEV-DO system by limiting a search time for the 1X system according to an embodiment of the present invention. It is a flowchart which shows the procedure which prevents cancellation | release.

  When the power is turned on by the user, the hybrid terminal 110 receives pilot signals from the 1X controller 132 and the 1X transmitter 122 of the 1X system, initializes the 1X mode, and is maintained in a standby state. Further, the hybrid terminal 110 uses the system parameter message obtained at the time of initializing the 1X mode and the pilot signals transmitted from the 1xEV-DO transmitter 124 and the 1xEV-DO controller 134 to perform the 1xEV-DO mode. After being initialized, the standby state is maintained (S500).

  The hybrid terminal 110 initializes the 1X mode and the 1xEV-DO mode, and then performs dual monitoring of the 1X system and the 1xEV-DO system. In this case, the hybrid terminal 110 monitors the 1xEV-DO system for 1 minute at 5.12 second intervals in the 1X mode, and thereafter monitors at 40 second intervals (S502).

  Meanwhile, the hybrid terminal 110 monitors the 1X system and the 1xEV-DO system in a standby state. In this state, when data is transmitted from the 1xEV-DO transmitter 124 to the hybrid terminal 110, or when data is requested to the 1xEV-DO system by key operation of the hybrid terminal 110, the 1xEV-DO mode is started. Then, it is confirmed whether or not the traffic state for data transmission / reception has been shifted (S504). In order for the hybrid terminal 110 to transition to the traffic state, a connection (connection) is established between the 1xEV-DO transmitter 124 and the 1xEV-DO transmitter 124 so that data can be transmitted and received between the hybrid terminal 110 and the hybrid terminal 110. ) And a session must be formed.

  When the hybrid terminal 110 shifts to the traffic state of the 1xEV-DO mode in step S504, the hybrid terminal 110 transmits / receives packet data to / from the 1xEV-DO system (S506).

  In step S506, the hybrid terminal 110 transmits and receives packet data to and from the 1xEV-DO system in a traffic state, and uses a built-in timer for a predetermined monitoring time (for example, for periodic search with respect to the 1X system). , 5.12 seconds) is checked (S508).

  When determining that the predetermined monitoring time has elapsed in step S508, the hybrid terminal 110 is switched to the 1X mode and starts searching for overhead messages of the 1X system (S510). In this case, the hybrid terminal 110 is switched to the 1X mode by the operation of the MSM chip and the searcher module.

  The hybrid terminal 110 is switched to the 1X mode by searching the 1X system so that it can answer a call from the 1X system, operates a built-in timer to check the search time, and receives and demodulates an overhead message. (S512). The hybrid terminal 110 continuously checks whether a predetermined search time (eg, 3.36 seconds) has elapsed while checking the search time through step S512 (S514).

  If the hybrid terminal 110 determines that the predetermined search time has elapsed in step S514, the hybrid terminal 110 stops the search operation for the 1X system, stores the received overhead message in the memory, and then returns to the 1xEV-DO mode. (S516). In addition, the hybrid terminal 110 that has returned to the 1xEV-DO mode repeats steps S510 to S516 after a predetermined monitoring time has elapsed.

  According to an embodiment of the present invention, when the hybrid terminal 110 that is in traffic with the 1xEV-DO system searches the 1X system for call answering or location registration in the 1X system, This eliminates the problem of call connection cancellation without using the resources of the 1X system and the 1xEV-DO system.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, this invention is not limited to this example. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

1 is a schematic block diagram illustrating a system for preventing a hybrid terminal from disconnecting a call by limiting a search time for a 1X system in a hybrid terminal according to an embodiment of the present invention; FIG. FIG. 3 is a block diagram illustrating a channel structure of a forward link for transmitting data to a hybrid terminal through a 1xEV-DO transmitter. FIG. 3 is a block diagram illustrating a channel structure of a forward link for transmitting data to a hybrid terminal through a 1xEV-DO transmitter. 2 is a block diagram illustrating a channel structure of a reverse link for transmitting data from a hybrid terminal to a 1xEV-DO transmitter. FIG. FIG. 6 is a diagram illustrating a procedure for preventing a hybrid terminal from disconnecting a call by limiting a search time for the 1X system of the hybrid terminal in a traffic state with the 1xEV-DO system according to an embodiment of the present invention. . According to an embodiment of the present invention, the search time for the 1X system is limited to prevent the call disconnection between the hybrid terminal 110 and the 1xEV-DO system in traffic with the 1xEV-DO system. It is a flowchart which shows a procedure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 System 110 Hybrid terminal 122 1X transmitter 124 1xEV-DO transmitter 132 1X controller 134 1xEV-DO controller 140 Mobile switching center 150 Packet data serving node 160 IP network

Claims (25)

The system prevents a call disconnection that occurs between the 1xEV-DO system and a hybrid terminal by limiting a predetermined search time for the 1X system in a traffic state with a CDMA2000 1xEV-DO (1xEV-DO) system. And
A 1X mode for receiving a voice signal transmission service or a low-speed data transmission service from the 1X system in conjunction with the 1X system, and a 1xEV-DO for receiving a high-speed data transmission service from the 1xEV-DO system in conjunction with the 1xEV-DO system. The 1xEV-DO mode is switched to the 1X mode periodically to update overhead messages in the traffic state with the 1xEV-DO system, and the 1xEV-DO mode when the predetermined search time elapses. Said hybrid terminal to be returned to;
A base station transmitter including a 1xEV-DO transmitter for transmitting / receiving packet data to / from the hybrid terminal and a 1X transmitter for transmitting / receiving voice or data to / from the hybrid terminal;
A base station controller including a 1xEV-DO controller that controls a packet data transmission service of the 1xEV-DO transmitter, and a 1X controller that controls a transmission service of the 1X transmitter;
A packet data serving node (PDSN) connected to the 1xEV-DO controller for transmitting and receiving the packet data to and from the 1xEV-DO system;
A system for preventing a call disconnection between the 1xEV-DO system and the hybrid terminal by limiting a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system.   The predetermined search time is for updating the overhead message used for call response and location registration in the 1X system after the hybrid terminal in traffic with the 1xEV-DO system is switched to the 1X mode. The time required for the 1xEV-DO system according to claim 1, wherein the predetermined search time for the 1X system is limited in a traffic state with the 1xEV-DO system according to claim 1, and the 1xEV-DO system and the hybrid terminal are connected. A system that prevents call disconnection that occurs between the two.   The hybrid terminal may stop searching for the 1X system and return to the 1xEV-DO mode when the predetermined search time elapses while the time for switching to the 1X mode elapses. A system for preventing a call disconnection that occurs between the 1xEV-DO system and a hybrid terminal by limiting a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system according to Item 1.   The hybrid terminal is set to the 1X mode to communicate with the 1X system in a standby state, and the 1xEV- is set at a predetermined time interval in order to check whether data has arrived through the 1xEV-DO system. The predetermined search time for the 1X system is limited in the traffic state with the 1xEV-DO system according to claim 1, wherein the mode is periodically switched to the DO mode and returns to the 1X mode again. A system that prevents call disconnection that occurs between a 1xEV-DO system and a hybrid terminal.   The hybrid terminal periodically receives the high-speed data from the 1xEV-DO system in the 1xEV-DO mode, and periodically enters the 1X mode at a predetermined time interval in order to check whether there is an incoming signal through the 1X system. The 1xEV-DO mode is limited to a predetermined search time for a 1X system in a traffic state with the 1xEV-DO system according to claim 1, wherein the 1xEV-DO mode is restored to the 1xEV-DO mode. A system that prevents call disconnection that occurs between the system and the hybrid terminal.   In the case of a forward link for transmitting data from the 1xEV-DO system to the hybrid terminal, a Time Division Multiple Access (TDMA) method is used, and data is transmitted from the hybrid terminal to the 1xEV-DO system. The reverse search link uses a Code Division Multiple Access (CDMA) method to limit a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system according to claim 1. A system for preventing a call connection cancellation between the 1xEV-DO system and the hybrid terminal.   In the case of the forward link, hard handoff is performed by transmitting data at maximum power without performing power control. In the case of the reverse link, power control is performed for each hybrid terminal. And performing a soft handoff in a traffic state with the 1xEV-DO system according to claim 6, wherein a predetermined search time for the 1X system is limited and the 1xEV-DO system and the hybrid terminal are connected. A system that prevents call disconnection that occurs between the two.   The hybrid terminal is switched from the 1xEV-DO mode to the 1X mode by tracking the frequency of the 1X system under the control of an MSM (Mobile Station Modem) chip. A system that prevents a call disconnection that occurs between the 1xEV-DO system and a hybrid terminal by limiting a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system according to 1. The forward link is a pilot channel used to send a pilot signal for tracking the hybrid terminal by the 1xEV-DO system;
A MAC (Medium Access Control) channel used to control the reverse link;
A control channel used to transmit a broadcast message or a direct message for directly controlling a specific hybrid terminal from the 1xEV-DO system to the hybrid terminal;
A traffic channel used to transmit only packet data from the 1xEV-DO system to the hybrid terminal;
The call connection that occurs between the 1xEV-DO system and the hybrid terminal by limiting a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system according to claim 6, System to prevent release.   The system further includes a mobile communication switching center that provides the communication connection path of the 1X system by switching a communication connection path for a communication call transmitted from the hybrid terminal. A system for preventing a call disconnection between the 1xEV-DO system and a hybrid terminal by limiting a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system according to claim 1. A method for preventing call disconnection by limiting a predetermined search time for a 1X system in a traffic state with a CDMA 2000 1xEV-DO (1xEV-DO) system,
(A) the hybrid terminal sequentially initializes the 1X mode and the 1xEV-DO mode and maintains a standby state;
(B) The hybrid terminal periodically and alternately monitors the 1X system and the 1xEV-DO system in the standby state;
(C) When the hybrid terminal shifts to the traffic state of the 1xEV-DO mode and a connection and a session are formed with the 1xEV-DO system, packet data is exchanged with the 1xEV-DO system. Making it possible to send and receive data;
(D) after the elapse of a predetermined monitoring time, the hybrid terminal is switched to the 1X mode;
(E) when the hybrid terminal is switched to the 1X mode, checking a switching time and detecting a signal of the 1X system;
(F) the hybrid terminal returns to the 1xEV-DO mode when the conversion time reaches a predetermined return start time;
A method of preventing a call disconnection between the 1xEV-DO system and the hybrid terminal by limiting a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system. In step (a),
The traffic state with the 1xEV-DO system according to claim 11, wherein the hybrid terminal initializes the 1xEV-DO mode using a system parameter obtained when the 1X mode is initialized. A method of preventing a call disconnection that occurs between the 1xEV-DO system and a hybrid terminal by limiting a predetermined search time for the 1X system in FIG. In step (d),
The traffic condition with the 1xEV-DO system according to claim 11, wherein the predetermined monitoring time is 5.12 seconds after the hybrid terminal is switched to the 1xEV-DO mode. A method for preventing a call disconnection that occurs between the 1xEV-DO system and a hybrid terminal by limiting a predetermined search time for the 1X system. In step (e),
The predetermined return start time is the change time at which the hybrid terminal converted to the 1X mode to detect the signal of the 1X system starts returning to the 1xEV-DO mode. [12] The call connection release between the 1xEV-DO system and the hybrid terminal is prevented by limiting a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system according to claim 11 Method. In step (e),
The method of claim 11, wherein the predetermined return start time is shorter than a call connection release time required for releasing a call connection between the hybrid terminal and the 1xEV-DO system. A method for preventing a call disconnection that occurs between the 1xEV-DO system and a hybrid terminal by limiting a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system.   The predetermined search start time for the 1X system in a traffic state with the 1xEV-DO system according to claim 15, wherein the predetermined return start time is set as an integer multiple of an SCI (Slot Cycle Index). A method of restricting and preventing call disconnection that occurs between the 1xEV-DO system and a hybrid terminal.   The predetermined search time for the 1X system in the traffic state with the 1xEV-DO system according to claim 15, wherein the predetermined return start time is set as 3.36 seconds or 4.48 seconds. A method of restricting and preventing call disconnection that occurs between the 1xEV-DO system and a hybrid terminal. In step (e),
The predetermined terminal for the 1X system in a traffic state with the 1xEV-DO system according to claim 11, wherein the hybrid terminal stores the overhead message received by the detection for the 1X system in a predetermined memory. A method for preventing a call disconnection that occurs between the 1xEV-DO system and the hybrid terminal by limiting a search time of the terminal. In step (f),
The hybrid terminal is returned to the 1xEV-DO mode by tracking a frequency used in the 1X-DO system using a searcher module under the control of a built-in MSM chip. [12] The method according to claim 11, further comprising: limiting a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system according to claim 11 to prevent a call disconnection that occurs between the 1xEV-DO system and the hybrid terminal.   The hybrid terminal according to claim 11 or 18, wherein the hybrid terminal uses the important overhead message received and stored in the previous search for the 1X system for the next search for the 1X system. A method for preventing a call disconnection that occurs between the 1xEV-DO system and a hybrid terminal by limiting a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system.   The overhead message according to claim 20, wherein the overhead message includes one or more of a system parameter message, an access parameter message, an extended system parameter message, a neighbor list parameter message, and a channel list parameter message. A method for preventing a call disconnection that occurs between the 1xEV-DO system and a hybrid terminal by limiting a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system. Hybrid terminal for preventing call disconnection between the 1xEV-DO system and the hybrid terminal by limiting a predetermined search time for the 1X system in a traffic state with the CDMA 2000 1xEV-DO (1xEV-DO) system Because
A timer for measuring the conversion time when converted from the 1xEV-DO mode to the 1X mode;
A searcher module that tracks and changes frequency to receive the overhead message to perform the conversion between the 1X mode and the 1xEV-DO mode;
A finger module for demodulating the overhead message received from the searcher module;
The MSM chip that periodically searches the 1X system and the 1xEV-DO system alternately and generates a return control signal and transmits it to the searcher module when a return start signal is received from the timer when searching for the 1X system When;
A hybrid terminal that prevents call disconnection by limiting a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system.   The 1xEV-DO according to claim 22, wherein the timer generates the return start signal and transmits it to the MSM chip when the measured conversion time reaches the predetermined return start time. A hybrid terminal that prevents a call disconnection that occurs between the 1xEV-DO system and a hybrid terminal by limiting a predetermined search time for the 1X system in a traffic state with the system.   The hybrid terminal operates in the 1X mode or the 1xEV-DO mode by searching for a frequency to be used in the 1X system or the 1xEV-DO system based on a predetermined monitoring period. 23. A hybrid terminal that prevents call disconnection between the 1xEV-DO system and the hybrid terminal by limiting a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system according to claim 22.   The MSM chip has information on a return start time, and generates and transmits the return control signal when confirming that the conversion time measured by the timer reaches the return start time. 23. A hybrid terminal that prevents call disconnection between the 1xEV-DO system and a hybrid terminal by limiting a predetermined search time for the 1X system in a traffic state with the 1xEV-DO system according to claim 22 Machine.

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